Mechanism for conveying and stacking individual sheets in overlapped groups



March 29, 1966 R. s. DEXTER ETAL 3,

' MECHANISM FOR CONVEYING AND STACKING INDIVIDUAL SHEETS IN OVERLAPPED GROUPS Filed Jan. 2, 1964 4 Sheets-Sheet l igzi INVENTORS ROBERT G. DXTR5 BY NORMRN D. SBUJYER R. G. DEXTER ETAL 3,243,182 MECHANISM FOR CONVEYING AND STACKING INDIVIDUAL March 29, 1966 SHEETS IN OVERLAPPED GROUPS 4 Sheets-Sheet 2 Filed Jan. 2, 1964 INVENTORS noes/er a. DXTR 6 BY NORmHN o. SnwYE'R 4!M-# a M March 29, 1966 R. G. DEXTER ETAL 3,243,182

MECHANISM FOR CONVEYING AND STACKING INDIVIDUAL SHEETS IN OVERLAPPED GROUPS Filed Jan. 2, 1964 4 Sheets-Sheet 5 k ml-1.151

Q INVENTORS I C power a.0xr,? a BY NORmHN D. SRWYCR March 29, 1966 R. G. DEXTER ETAL 3,243,182

MECHANISM FOR CONVEYING AND STACKING INDIVIDUAL SHEETS IN OVERLAPPED GROUPS 4 Sheets sheet 4 Filed Jan. 2, 1964 r INVENTORS Ross/Pr a. 05x75 6' BY uonnnu a. shaman a ITTOIP/VEVS United States Patent 3,243,182 MECHANISM FOR CONVEYEJG AND STACKING INDIVIDUAL SHEETS IN OVERLAPPED GROUPS Robert G. Dexter, Harvard, and Norman D. Sawyer, West Acton, Mass., assignors, by mesne assignments, to Riegel Textile Corporation, New York, N.Y., a corporation of New York Filed Jan. 2, 1964, Ser. No. 335,320 6 Claims. (Cl. 27174) This invention relates to a conveying and stacking mechanism for individual cut sheets of material and particularly to a mechanism which will stack these cut sheets of material in stacks of a predetermined number shingled or overlapping each other in such a manner that the leading stack can easily be removed by an operator without disturbing the remaining stacks.

Heretofore, conveying and stacking mechanisms have stacked in a predetermined number of cut sheets of material in separate, non-contacting stacks. This method of stacking cut sheets required a large conveyor area since each stack required an area of conveyor space equal to its own dimensions. This resulted in very large machines and a waste of space.

Generally, this invention provides a conveying and stacking mechanism which will overcome the problem set out above inasmuch as the mechanism of this invention provides for stacking cut sheets of material in separate stacks for a predetermined number which overlap each other or are shingled together and thereby conserve space along the conveyor.

This method of stacking presented a further problem in that the leading stack of cut sheets on the conveyor was necessarily underneath the stack that followed it because the leading stack was formed first and indexed forward on the conveyor and then the next stack was formed with part of the second stack shingled or overlapping the first stack. This presented a problem to the operator when removing the leading stack, since the operator necessarily had to either pull the leading stack out from the under the stacl; that followed it or lift the stack that followed for removal of the leading stack. This method of removal sometimes resulted in disturbing the stacks of cut sheets which followed the leading stack being removed.

Accordingly, another feature of this invention is the provision of a conveyor system or feeding system which will convey the cut sheets of material after they have been stacked in a predetermined number through an angle of 180 degrees to reverse the overlapping or shingling to present the leading stack on the top of the stack which follows for easy removal by the operator.

One illustrative but non-limiting example of this invention provides a conveying and stacking device which comprises a vacuum transfer conveyor mechanism for transferring cut sheets of material from a conventional conveyor system, where the material has been cut or subsequent operations have been performed thereon, to the feeding and stacking device of this invention. From the vacuum transfer the inividual cut sheets are conveyed to the stacker mechanism where a photo-electric cell actuates suction mechanisms to stack a predetermined number of cut sheets in a stack. The photocell also actuates the conveyor on which the stacks are made, to index this conveyor forward a distance less than the length of the stack of cut sheets, so that another stack may be made which overlaps or shingles the first stack. The stacks are indexed by the last mentioned conveyor through an angle of 180 degrees to invert the shingling or overlapping, so that an operator may easily remove the leading stack from the mechanism.

The foregoing conveying and stacking method and apparatus may be applied to individual cut diapers which have been cut from a traveling web of textile material as disclosed in our copending application Serial No. 339; 839, filed December 31, 1963. However, it is to be understood that this invention may have application to any cut sheets of material which are to be stacked for easy handling by an operator.

Further features of the invention will be understood from a consideration of the following more detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of the conveying and stacking mechanism;

FIG. 2 is a diagrammatic side elevational view of the front half of the mechanism illustrated in FIG. 1;

FIG. 3 is a diagrannnatic side elevational vew of the rear half of the mechanism illustrated in FIG. 1 and is a continuation thereof;

FIG. 4 is a partial diagrammatic side elewational closeup of the tail-end grab mechanism; and

FIG, 5 is a partial bottom view of the tail-end grab device.

Referring to FIGS. 1 and 2, individual cut sheets of material 10 are led from a conventional conveyor 11 to a vacuum transfer conveyor 12. The vacuum transfer conveyor 12 comprises a plurality of conveyor bands 13 having apertures 14 therein. The conveyor bands 13 are disposed around drive rolls 15, 16, and 17 and are rotated thereon in a direction shown by the arrows in FIG. 2. A suction is supplied to the inside of the bands 13 by an air suction conduit 18 which exerts a suction on the inside of the bands 13. Therefore, as may be seen in FIG. 2, when a cut sheet of material 10 is led to the conveying and stacking mechanism of this invention from a conventional conveyor 11, the cut sheets 10 will pass under the vacuum transfer conveyor 12 which through the suction exerted on the inside of the rotating bands 13 and the apertures 14 will suck the cut sheets 10 onto the outside of rotating bands 13 where they will be transferred to the intermediate conveyor belts 63 and 19.

The intermediate conveyor belt 63 is disposed around drive rolls 20, 21, 22, 23, and 24 and is rotated thereon in the direction shown in FIG. 2. The intermediate conveyor belt 19 is disposed around drive rolls 25, 26, and 27 and is rotated thereon in the direction shown in FIG. 2. These intermediate conveyor belts 63 and 19 convey the cut sheets 10 to the stacking device of this invention.

The stacking device of this invention comprises a stacking conveyor 28. The stacking conveyor 28 is similar to the transfer conveyor 12 in that it comprises a plurality of conveyor bands (not shown) having apertures 29 therein. The stacking conveyor bands 28 are disposed around drive rolls 30 and 31 and are rotated in the direction shown by the arrows in FIGS. 2 and 3. Disposed on the inside of stacking conveyor 28 and adjacent the inside surface are first suction chamber 32 and second suction chamber 33, as shown in FIGS. 2 and 3. The first suction chamber 32 has a constant suction therein which is created by air suction conduit 34, as shown in FIG. 1. The second suction chamber has. a suction therein which may be cut on and off by air suction conduit 35. These suction chambers create a suction on the inside of stacking conveyor belts 28 and therefore, suck the cut sheets 10 onto the conveyor belts 28 by means of apertures 29 to be conveyed along as conveyor belts 28 are moved.

The stacking mechanism further includes a tail-end grab device indicated generally at 36. This tail-end grab device includes a body portion 37 having a sheet contacting surface 38 with apertures 48 therein and which is movably pivoted at 39 to a bell crank (see 3 FIGS. 4 and 5) having arms and 41. Arms 40 are further pivoted to fixed pivot shaft 42. Arms 41 are further controlled at 43 and 44 by eccentric cams 45 and 46 which are mounted on and driven by shaft 47. The body portion 38 of the tail-end grab is provided with a suction created by an air suction conduit (not shown) which is stronger than the suction provided in the first and second suction chambers 32 and 33. The body portion 38 is maintained in the positions illustrated in FIG. 4 relative to hell crank arm 40 by a compression spring 48 secured to body portion 37 and spring arm 49 fixed to and movable with arm 40.

Included in the stacking mechanism is a first exit conveyor 50 which is disposed around and driven by drive rolls 5]., 52, 53 and 54 in the direction shown by the arrows in FIGS. 2 and 3. Cooperating with the exit conveyor 50 are a plurality of idler rollers 55, as shown in FIGS. 2 and 3, which hold the conveyor in the desired position,

Cooperating with the aforementioned parts of the stacker mechanism is a conventional photocell 56 and light supply 57. The photocell and light supply are located adjacent the front end of the first suction chamber 32 and are disposed opposite sides of the intermediate conveyor 63 such that a cut sheet will acutate the photocell and light supply. The photocell is adapted to cut the suction for the second suction chamber 33 on and off, actuate the shaft 47, and actuate the drive rolls for exit conveyor 50 through any suitable electrical connections including electric motors and time delay relays.

In operation, the cut sheets 10 are being conveyed toward the stacking mechanism by intermediate conveyors 63 and 19. The leading cut sheet then passes between the photocell 56 and light source 57 and the trailing edge actuates photocell 56. This cut sheet is then sucked up onto stacking conveyor 28 by the first suction chamber 32. The cut sheet is conveyed along by this conveyor and is led under the second suction chamber 33 which holds the cut sheet on the conveyor 28. Concurrently with this conveying action, the drive shaft 47 is rotated by any convenient means (not shown) which has been actuated by the photocell. The rotation of the shaft 47 rotates eccentric cams 45 and 46 which causes a movement of the bell crank and tail-end grab mechanism 36 from the position shown in dotted lines in FIG. 4 to the solid line position of that figure. This motion of the tail-end grab device 36 is so timed as to cause the tail-end grab device to contact the tail end of the cut sheet 10 which is being carried by the stacking conveyor 28. The suction exerted in the tail-end grab device 36 is greater than the suction in the second suction chamber 33, so that the cut sheet 10 will be held stationary by the tail-end grab device and thereby slip on the stacking conveyor 28. Subsequent to this grabbing action the suction is cut off in the second suction chamber 33 by a time delay relay and suitable electrical circuit (not shown) which is actuated by the photocell 56. This results in the leading cut sheet 10 being dropped onto the exit conveyor 50 which is not moving. The tail end grab device 36 then completes its cycle by lowering under the action of arm 40, the vacuum cuts off in it and it swings to the dotted line position of FIG. 4 by the action of arm 41. The leading cut sheet 10 is now resting entirely on the exit conveyor 50 which is not moving. This sequence of operations is repeated until a predetermined number of cut sheets 10 are stacked in a stack. At this time the photocell actuates a suitable electrical circuit, present counter, and motor (not shown) to index the exit conveyor forward, a distance less than the length of a cut sheet 10, in the direction of the arrows in FIGS. 2 and 3. The above described sequence of operations is then repeated to form other stacks of cut sheets 10 which overlap or shingle the stack which preceeds it.

Cooperating with the exit conveyor 54) is second exit conveyor 58. The second exit conveyor 58 is disposed around and driven by drive rolls 59, 60, and 61 in the direction shown by the arrows in FIG. 3. There are provided a plurality of idler rollers 62 for holding the second exit conveyor 58 in the desired position. The drive rollers for the first exit conveyor 50 and for the second exit conveyor 58 are driven simultaneously.

The aforementioned first and second exit conveyors 5t} and 58 are so arranged, as shown in FIG. 3, as to be adapted to squeeze the shingled stacks of cut sheets 10 between them and convey these stacks through an angle of degrees to invert the shingling or overlapping of the stacks so that the leading stack, as shown in FIG. 3, can be easily removed by an operator without disturbing the remaining stacks.

The mechanisms described above may be driven mechanically by any convenient chain or motor drives, some of which are shown in FIG. 1. However, these drive mechanisms do not constitute a part of this invention and have not been described in detail here.

This invention is not intended to be limited by the foregoing description or otherwise except as defined in the appended claims.

\Ve claim:

1. Sheet conveying and stacking means for conveying and stacking individual cut sheets into shingled, overlapping stacks of a predetermined number of cut sheets comprising a conveyor means for conveying the individual cut sheets to the stacker mechanism, a stacker means for stacking the individual cut sheets into overlapping, shingled stacks of a predetermined number of cut sheets, exit conveyor means for conveying the overlapping, shingled stacks of cut sheets through an angle of 180 degrees so that the leading stack of cut sheets can be easily removed from the exit conveyor, and a vacuum transfer conveyor means for transferring the individual cut sheets to the conveying and stacking mechanism comprising a plurality of conveyor belts disposed around and driven by a plurality of drive rolls, said conveyor belts having a plurality of apertures therein, and a suction means for producing a vacuum in said vacuum transfer conveyor means to enable the vacuum transfer conveyor means to suck the individual cut sheets onto said conveyor hands by means of said apertures for the transfer operation.

2. Sheet conveying and stacking mechanisms, as set forth in claim 1, in which, said stacker means comprises a photocell and light supply, a stacking conveyor partially disposed over said exit conveyor comprising a plurality of conveyor bands having apertures therein and being disposed around and driven by a plurality of drive rolls, a first suction chamber means disposed adjacent the inside surface of said stacking conveyor bands for sucking the individual cut sheets onto said stacking conveyor means for movement therewith, a second suction chamber means disposed adjacent the inside surface of said stacking conveyor bands and adjacent said first suction chamber means for holding the individual cut sheets on said stacking conveyor means after they have traveled past said first suction chamber means, said photocell being adapted to cut the suction on and off in said second suction chamber means so that said out sheets may drop onto said exit conveyor to stack the individual cut sheets in stacks, and said photocell being adapted to actuate said exit conveyor to index it forward a distance less than the length of the cut sheets for forming another stack which overlaps and shingles the first stack.

3. A sheet conveying and stacking mechanism, as set forth in claim 2, in which said stacker mechanism further includes a tail end grab means including a suction means therein which is actuated by said photocell to grab the tail end of the cut sheets as they are being held on said stacking conveyor by said second suction chamber means to ensure a straight stack is formed when the cut sheets are released by said second suction chamber means.

4. A sheet conveying and stacking mechanism, as set forth in claim 1, in which said exit conveyor means comprises a first conveyor belt disposed around and driven by a series of drive rolls and a second conveyor belt disposed around and driven by a second series of drive rolls, said first and second conveyor belts being disposed adjacent each other for 180 degrees so that the shingled stacks of cut sheets may be sandwiched therebetween and conveyed through an angle of 180 degrees.

5. A stacker mechanism including an exit conveyor means comprising a photocell and light supply, a stacking conveyor partially disposed over said exit conveyor comprising a plurality of conveyor bands having apertures therein and being disposed around and driven by a plurality of drive rolls, a first suction chamber means disposed adjacent the inside surface of said stacking conveyor bands for sucking the individual cut sheets onto said stacking conveyor means for movement therewith, a second suction chamber means disposed adjacent the in side surface of said stacking conveyor bands and adjacent said first suction chamber means for holding the individual cut sheets on said stacking conveyor means after they have traveled past said first suction chamber means, said photocell being adapted to cut the suction on and off in said second suction chamber means so that said cut sheets may drop onto said exit conveyor to stack the individual cut sheets in stacks, and said photocell being adapted to actuate said exit conveyor to index it forward References Cited by the Examiner UNITED STATES PATENTS 2,082,240 6/ 1937 Belluche et a1. 271-46 2,177,460 10/ 1939 Renz 271-76 2,197,573 4/ 1940 Tollison 27176 2,268,304 12/ 1941 Rapley 271-76 2,541,752 2/1951 Eddy et a1 27176 2,852,256 9/ 1958 Faulls et 3.1. 2,9 19,789 1/ 1960 Coakley 27146 X FOREIGN PATENTS 970,959 9/ 1964 Great Britain. 336,846 4/ 1959 Switzerland.

M. HENSON WOOD, JR., Primary Examiner.

A. KNOWLES, Assistant Examiner. 

1. SHEET CONVEYING AND STACKING MEANS FOR CONVEYING AND STACKING INDIVIDUAL CUT SHEETS INTO SHINGLED, OVERLAPING STACKS OF A PREDETERMINED NUMBER OF CUT SHEETS COMPRISING A CONVEYOR MEANS FOR CONVEYING THE INDIVIDUAL CUT SHEETS TO THE STACKER MECHANISM, A STACKER MEANS FOR STACKING THE INDIVIDUAL CUT SHEETS INTO OVERLAPPING, SHINGLED STACKS OF A PREDETERMINED NUMBER OF CUT SHEETS, EXIT CONVEYOR MEANS FOR CONVEYING THE OVERLAPPING, SHINGLED STACKS OF CUT SHEETS THROUGH AN ANGLE OF 180 DEGREES SO THAT THE LEADING STACK OF CUT SHEETS CAN BE EASILY REMOVED FROM THE EXIT CONVEYOR, AND A VACUUM TRANSFER CONVEYOR MEANS FOR TRANSFERRING THE INDIVIDUAL CUT SHEETS TO THE CONVEYING AND STACKING MECHANISM COMPRISING A PLURALITY OF CONVEYOR BELTS DISPOSED AROUND AND DRIVEN BY A PLURALITY OF APERTURES THEREIN, AND A SUCTION MEANS FOR PLURALITY OF APERTURES THEREIN, AND A SUCTION MEANS FOR PRODUCING A VACUUM IN SAID VACUUM TRANSFER CONVEYOR MEANS TO ENABLE THE VACUUM TRANSFER CONVEYOR MEANS TO SUCK THE INDIVIDUAL CUT SHEETS ONTO SAID CONVEYOR BANDS BY MEANS OF SAID APERTURES FOR THE TRANSFER OPERATION. 